Cloned animal cells may help treat Parkinson's disease

ATLANTA (CNN) -- Researchers are using cloned animal cells in an attempt to ease the tremors and erratic movements caused by Parkinson's disease.

Researchers at the University of Colorado transplanted cloned bovine brain cells into the brains of rats. The cloned cells were effective in treating the symptoms of Parkinson's in the rats.

"What we found was that the bovine fetal dopamine cells were just as good as bovine embryo cells from an animal that was not cloned," said Dr. Curt Freed of the University of Colorado.

By using the cloned cells, the scientists hope to replace the brain's dwindling supply of dopamine-producing cells to ease tremors. Cloning often raises fears, but researchers say there's a big difference between cloning brain cells and cloning humans.

"There's no relationship between cloning cows or cloning sheep or cloning pigs for therapeutic uses and the potential for cloning human beings," Freed said.

Others also are experimenting with using animal cells to treat Parkinson's. Researchers at Emory University are preparing to transplant pig cells into humans later this year.

Dolly the cloned sheep

Dr. Ray Watts of Emory said there are advantages to using cloned cells. "One potential advantage of cloning is to produce identical cells, genetically identical cells," he said. With cloned cells, the chance of rejection is lower but not eliminated.

Using transplanted animal cells, however, raises the concern that unknown viruses could be passed on to humans.

"That's an unknown issue at this point," Watts said. "It's certainly something everyone thinks about, is concerned about, appropriately, but to date there's been no example of that."

Researchers are not ready to use the cloned cells in people. But if the technique proves successful, it could be used to treat other diseases like diabetes.